Two important Iron Age civilizations were the Greeks and Romans. Greek civilization made major contributions to philosophy with thinkers like Socrates, Plato, and Aristotle. They also advanced mathematics, medicine, theatre, history, and sculpture. Roman civilization began along the river Tiber in Italy and was defined by constant war and agriculture. The Romans contributed greatly to art, literature, architecture by building roads, bridges, and aqueducts to transport water across basins. Urban life expanded as trade and artisans became important in Roman cities.